I got a betta maybe two days ago and I noticed she has a fin that's sorta bent. It's one of the fins at the bottom... I don't know the name of the fins yet :). The other one is fine. Could it be clamped? She doesn't seem stressed. She eats. I was just wondering if I should be worried. It kind of looks like a sideways L. I'll fill this out.

Housing
What size is your tank? 2.5 gallons
What temperature is your tank? probably 76-78ish
Does your tank have a filter? Yes, I dont use it. It makes a lot of current
Does your tank have an air stone or other type of aeration? Nope.
Is your tank heated? No. It is under the heating vent in the warmest room of the house though, so it is really warm. (It's warm here)
What tank mates does your betta fish live with? Not any, she does have a tiny Crowntail female next to her (not divided, separate tank) if that helps! She had the fin before she came.

Food
What type of food do you feed your betta fish? New Life Spectrum Betta Formula (small pellets)
How often do you feed your betta fish?
2-4 pellets in the morning and at night.
Maintenance
How often do you perform a water change? Havent made a real number, but I changed 5% today. It's still clean.
What percentage of the water do you change when you perform a water change? Same as above.
What type of additives do you add to the water when you perform a water change? When I first put her water in I put Betta water conditioner and
a tiny bit of AQ salt.

Water Parameters:
Have you tested your water? If so, what are the following parameters?
Nope.
Nitrate:
pH:
Hardness:
Alkalinity:

Symptoms and Treatment
How has your betta fish's appearance changed? No, it's been the same.
How has your betta fish's behavior changed? No, she's exploring and eating.
When did you start noticing the symptoms? Yesterday or so.
Have you started treating your fish? If so, how? Nope, unless you include the AQ salt i put in when it was cycling.
Does your fish have any history of being ill? Nope, she seems perfect, just the L shaped fin is all.
How old is your fish (approximately)? Hard to tell got her 2 days ago :)

It may have been damaged or a birth defect- it should not cause discomfort or lessen her quality of life. There is no cure for it, just make sure to do the weekly water changes and feed a varied diet high in protein to keep her, and her fins healthy. I am believing you are meaning the ventral/pelvic fins- the two on the bottom by her belly?

If there is still AQ salt in there.. I would do some large water changes, or a 100% to remove the salt- as long term exposure can harm them by causing kidney and liver failure... Only use tap water and water conditioner for each water change.

In a 2.5 your tank will not establish a true cycle as the water surface is too small- you will build up a nitrogen cycle, but in a 2.5 unfiltered tank there is nothing other then possibly some bacteria in the gravel.

In a 2.5 tank with no filter you will want to do weekly 1 50% and 1 100% water change- as there is no cycle in it. If you wish to use the filter then clean it out completely as any bacteria that had grown in it is now dead and will be pushed into the tank once more if you turn it on without cleaning.. you can always baffle the filter using an AQ sponge in the outflow to slow it down if you wish to use it- it will eliminate the need for a 100%, but you would still need to be doing weekly water changes with siphoning/vacuuming of the gravel.

On a side note- even though it's under a heat duct, make sure that the temp in her tank does not fluctuate too much, as fluctuations could cause shock. The turning on and off of the heater may cause it, even just a few degrees can be deadly if it drops/raises too quickly.

I baffled the filter with a sponge Thanks so much!! I will vaccum it maybe Sunday or so. Would that be ok? Theres not much gravel in it. (Theirs a rather large hideyhole that makes it pretty slim around it.)